indicated early by Boden (1952) . He commented that animals in 

 Bermuda breed during months when wind driven circulation is at a 

 minimum. At this time, a convergence between warm and cold water 

 currents occur, and anticyclonic eddies form. Boden discovered 

 that plankton accumulated in this region of the convergence. 

 Emery (1972) reported a similar situation for the island of Bar- 

 bados, West Indies, and provided evidence for the existence of 

 eddies in the island's lee. Planktonic larvae in these eddies 

 ostensibly avoid being swept away from the island (Emery 1972) . 

 Eddies discovered in Hawaiian waters have been similarly impli- 

 cated by Jones (1968) . Evidence for the function of eddies in 

 preventing loss of larvae from Hawaiian waters and maintaining 

 fish larvae of the family Acanthuridae near shores was later 

 obtained by Sale (1970) . He presented data suggesting that the 

 surface eddies were effective in trapping planktonic larvae which 

 then were revolved past the island of Oahu (about 25 to 50km from 

 shore) every five to six days (see also Leis and Miller 1976) . A 

 key feature of the Hawaiian eddies is that some remain in the 

 vicinity of the islands for at least 65 days, (Patzert 1967, 

 Lobel and Robinson, in prep.), which is sufficient time for 

 development of some larvae into a stage capable of migrating back 

 to the inshore habitat (eg., Acanthurus triostegus sandvicensus , 

 Randall, 1961; Chaetodon milaris . Ralston 1976) . 



The biological importance of retaining planktonic eggs and 

 larvae near shore to the maintenance of island populations is 

 obvious. However, the behavioral and physical mechanisms by 

 which planktonic larval fishes return have not been elucidated 

 and the potential role of eddies has not been widely recognized. 



It is well known, for example, that the larvae of fishes 

 which dominate Hawaiian inshore habitats (e.g., labrids, scarids, 

 acanthurids, and chaetodontids) are nearly absent from inshore 

 waters, but instead are found offshore many kilometers away 

 (Miller 1973) . Many Hawaiian fishes display a collective spawn- 

 ing peak in the spring (Watson and Leis 1974, Lobel 1978). Wat- 

 son and Leis (1974) suggested that the spring spawning peak was 

 an adaptation to local currents. A general shift in the prevail- 

 ing large scale currents around the Hawaiian Islands occurs in 

 late spring and again in the fall (Barkley e_t al. 1964) . Watson 

 and Leis (1974) proposed "These shifts, which should be associ- 

 ated with weaker currents, occur with spring and fall spawning 

 peaks. Synchronization of spawning with periods of reduced 

 current flow would allow development and metamorphosis of the 

 pelagic larvae before they were swept out to sea" (see also 

 Johannes 1978) . Additional evidence suggests that it is not the 

 shifts in prevailing currents, per se , but the offshore eddies 

 and other variable mesoscale currents which form during those 

 times which may be the important factor involved (Lobel 1978) . 



We have suggested a relationship between the occurrence of 

 ocean eddies and the distribution and abundance of coastal marine 

 larvae. If this relationship is approximately true, then we 

 expect the following, given two alternative environmental cir- 

 cumstances: 



33 



